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Possible Tranny Problem...?

1K views 25 replies 9 participants last post by  IvanC 
#1 ·
To all you gifted techs,

Why does my car sound like it is grinding when I'm going in reverse? It sounds like gears are grinding. Also when driving down the road in 1st-3rd gears and I let off the gas (even gently) I hear the grinding sound again. I would like to fix this problem as soon as possible. Thanks to everyone!

1991 Nissan NX2000
 
#2 ·
When was the last time your transmission fluid was changed? If recently, then first thing to do is check your fluid (use a good quality 3/8 drive ratchet head to undo the fill plug), dip a finger in there -- you should feel fluid immediately. If not, fill with some GL3 75w90 (get a funnel w/ long flexible tube) until it starts to drip out of the hole.

The best suggestion however, is to completely drain (need a 1/2 drive ratchet head or better, a 1/2 breaker bar) and re-fill your transmission with ~3.5 qts of Redline MT90 fluid ($7 a qt.) Let us know how it feels.
 
#3 ·
IvanC said:
When was the last time your transmission fluid was changed? If recently, then first thing to do is check your fluid (use a good quality 3/8 drive ratchet head to undo the fill plug), dip a finger in there -- you should feel fluid immediately. If not, fill with some GL3 75w90 (get a funnel w/ long flexible tube) until it starts to drip out of the hole.

The best suggestion however, is to completely drain (need a 1/2 drive ratchet head or better, a 1/2 breaker bar) and re-fill your transmission with ~3.5 qts of Redline MT90 fluid ($7 a qt.) Let us know how it feels.
I'll try this! Thank-you very much!
 
#9 ·
Storm88000 said:
Grinding into reverse is somewhat normal. Sometimes I need to depress the clutch twice to get it into reverse.
I've been wondering about this for years but I have never brought it up to anyone.

I usually need to double clutch to get into reverse.

Is it a synchro thing ? ....
 
#10 ·
NismoNX said:
To all you gifted techs,
Also when driving down the road in 1st-3rd gears and I let off the gas (even gently) I hear the grinding sound again. I would like to fix this problem as soon as possible. Thanks to everyone!

1991 Nissan NX2000
This sounds like a collapsed motor mounts.

You might want to look at your passanger side motor mount and see if there are rips or if it looks collapsed. You can go with the ES (Energy Suspension) insert, this is a cost effective fix and does not take much time to do with some basic mechanic skills. The other option is to just replace your passanger side motor mount with the factory liquid filled piece. This is quite expensive though, and I noticed no difference (except at idle) with extra vibrations from the solid ES insert.

Do a search on motor mount inserts, if you are interested in the more cost affective route of ES inserts, there has been alot of talk/write-up's about this...

Good luck, and where in Idaho are you? I'm in Pullman, WA.
 
#11 ·
McCoy said:
This sounds like a collapsed motor mounts.

You might want to look at your passanger side motor mount and see if there are rips or if it looks collapsed. You can go with the ES (Energy Suspension) insert, this is a cost effective fix and does not take much time to do with some basic mechanic skills. The other option is to just replace your passanger side motor mount with the factory liquid filled piece. This is quite expensive though, and I noticed no difference (except at idle) with extra vibrations from the solid ES insert.

Do a search on motor mount inserts, if you are interested in the more cost affective route of ES inserts, there has been alot of talk/write-up's about this...

Good luck, and where in Idaho are you? I'm in Pullman, WA.
Hey thanks! I'll look into that. I also noticed when I go over a curb or speed bump in even neutral, It makes the same grinding noise. When I drag the motor seems to torque a little too much for the 130ft/lbs that it puts out. Motor mounts make sense. Do you have a link to where I can buy these inserts?
Also, I'm from Boise, Idaho. Rarely do I see any people sporting the sr20 in my area. The ones that I see are usually older people also. This area is big into modded civics. I've never lost to a b16 yet however! When I race or show my car, people are very curious to what it is exactly! I'd like to see more sr20s over here and possibly set up a caravan to the Convention...
 
#16 ·
Storm88000 said:
I'm assuming Nissan made it hard to get into reverse so you accidently didn't shift into reverse while driving down the highway....
Not quite. It's two things:

1. Reverse gear doesn't have a synchro in these transmissions.
2. It's mechanically impossible to shift into reverse while moving forwards as the reverse gear is constantly moving in the opposite direction as all of the forward gears.

If you want to make shifting into reverse easier, double clutch and/or momentarily shift into a forward gear (with the clutch pedal down) before shifting into reverse. If need to quickly transition from a forward gear to reverse, leave the car in that gear, stop completely (leave the clutch pedal down), then immediately shift into reverse.

If you're still having trouble getting into reverse, check to make sure the clutch is disengaging completely when you push the pedal down.
 
#17 ·
IvanC said:
When was the last time your transmission fluid was changed? If recently, then first thing to do is check your fluid (use a good quality 3/8 drive ratchet head to undo the fill plug), dip a finger in there -- you should feel fluid immediately. If not, fill with some GL3 75w90 (get a funnel w/ long flexible tube) until it starts to drip out of the hole.

The best suggestion however, is to completely drain (need a 1/2 drive ratchet head or better, a 1/2 breaker bar) and re-fill your transmission with ~3.5 qts of Redline MT90 fluid ($7 a qt.) Let us know how it feels.
I'm going to sound like a complete idiot, but here it goes! Where is my trnasmission fluid dipstick!?! The transmission is on the right side of the engine while staring at it from in front of the car, but no dipstick or reservoir can be seen. It is really annoying me. I'm at school and do not have my shop manual with me, and would like to check it before I leave. Please help!
 
#19 ·
reverm said:
Manual transmissions don't have a dipstick (well, they usually don't). You have to take off the drain plug and stick something in there. I normally like putting a ruler in. Other people use their finger. Hey, whatever works.
Hi,
That makes complete sense. The drain plug is on the bottom of the transmission correct (or else the fluid would not drain)? If so, as soon as I put my finger in there, it will start to leak. How do I know whether it is full or not also?
 
#20 ·
NismoNX said:
Hi,
That makes complete sense. The drain plug is on the bottom of the transmission correct (or else the fluid would not drain)? If so, as soon as I put my finger in there, it will start to leak. How do I know whether it is full or not also?
Actually, there is a drain plug (for draining the tranny fluid) and a fill plug (for filling the tranny).

You want to take the fill plug off [location is halfway up the tranny housing toward the radiator] and poke your pinky finger around for tranny fluid...
 
#21 ·
McCoy said:
Actually, there is a drain plug (for draining the tranny fluid) and a fill plug (for filling the tranny).

You want to take the fill plug off [location is halfway up the tranny housing toward the radiator] and poke your pinky finger around for tranny fluid...
Sorry. I'm just used to calling it a drain plug for some bizzare reason. It's the fill plug though.
 
#22 ·
I think you should be examining your passenger motor mount as well, it was suggested before and is probably the culprit to the noise. they usually make a groan when they are bad and make noise when you are decelerating(foot off the gas). cheapest fix is the engergy suspension insert. it is really had to get your old mount out of the casting though, i used a small sledge hammer, it is a pain in the rear though.
 
#23 ·
McCoy said:
Actually, there is a drain plug (for draining the tranny fluid) and a fill plug (for filling the tranny).

You want to take the fill plug off [location is halfway up the tranny housing toward the radiator] and poke your pinky finger around for tranny fluid...
Ok, thanks!
So If I put my finger in and don't feel oil then I add some. How much? I assume that if I do feel tranny fluid than the level is ok. Thanks a bunch...What is the absolute best tranny fluid? Money is no object. Thanks...!
 
#24 ·
just drain it and put in some redline mt-90. my opinion. maybe some other guys will recomend the blue or purple stuff, i dont remember the name...
 
#25 ·
IvanC said:
When was the last time your transmission fluid was changed? If recently, then first thing to do is check your fluid (use a good quality 3/8 drive ratchet head to undo the fill plug), dip a finger in there -- you should feel fluid immediately. If not, fill with some GL3 75w90 (get a funnel w/ long flexible tube) until it starts to drip out of the hole.

The best suggestion however, is to completely drain (need a 1/2 drive ratchet head or better, a 1/2 breaker bar) and re-fill your transmission with ~3.5 qts of Redline MT90 fluid ($7 a qt.) Let us know how it feels.
Hi,
Would fully synthetic gear oil 75w-90 help my tranny since I drag quite a bit?
 
#26 ·
I don't personally have experience with synthetics, although some people enjoy using Mobil and Valvoline synthetics.

Based on the collective list and forum experience, Redline MT-90 is highly recommended. I've used it for years. Some others swear by Royal Purple, but someone mentioned it was GL-5 (as well as being "GL-4" rated), so they were wary of it.
 
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